I'm looking for some sort of easy to use webservice that allows you to plan and track projects. Something reasonably easy to use, thats easy to install on your own webspace, and that is easy to edit without going into code. You know, some sort of web site that allows you to create a project, put in milestones and then allow people to log in and see progress. A sort of Microsoft Project just as a web service.

Does anyone know about any such thing out there?

I'm thinking of using a simple Wiki, where people log in and just edit documents, but I would like something more robust where you can actually put in dates and see progress on specific projects.